What legal rules must colleges and universities follow when it comes to speech on campus? And, beyond legal requirements, what is a school's obligation to protect – or limit – free speech?

Students for a Democratic Society was the largest – and arguably most successful – student activist organization in U.S. history.
S.Sgt. Albert R. Simpson, Department of Defense / via WikimediaMay 3, 2017

UC Berkeley had a duty to protect the free speech of right-wing provocateur Milo Yiannopoulos and those protesting his appearance. But what are the limits of free speech when it comes to campus safety?